Hazard wrote:That's a rather common thing, Ranma is the last remaining Black... No, it would be more fun if she becomes the Heir to the Blacks because of some random process.
Here goes some alternative to Ranma being related to Sirius by blood.
Ranma is the adopted son of Sirius Black.
How? Before Harry's birth, Sirius traveled to other countries, and somehow met Genma, who sold Ranma to Sirius for something. However this transaction was documented, with both Sirius and Genma's signature and hanko (seal), and certified by official channels. Some clauses says that Ranma would stay with his original family until his tenth anniversary, when he would go to Sirius family care.
Why Sirius would do something like that? Maybe in spite to his family.
Another tiny possibility is that Ranma is a muggleborn wizard. In other words, he have access to magic, but he doesn't know how to use it, since he didn't have access to the magical world education. Or maybe he can access it by using martial arts. His ki is saturated with magic, so it can affect magical creatures.
So the will would reflect Ranma's status as Sirius son, leaving to Ranma and Harry all of his possessions. In other side, if the Malfoys end invalidating Sirius will, or making Harry arrives late to the hearing, all of Sirius possessions will go to Ranma, since he is Sirius son, fact that the Malfoys doesn't know.